Surveillance systems are known wherein a camera is mounted within a dome-shaped housing assembly comprised of an upper housing of generally hemispherical configuration with a "bubble" of like configuration releasably joined to the upper housing and comprised of material permitting the camera to view the surveillance zone therethrough. The camera is mounted for panning, i.e., rotation about a vertical axis, and for tilting motion relative to the horizontal. Coutta U.S. Pat. No. 3,935,380, which issued on Jan. 27, 1976, depicts such apparatus for indoor use, as in monitoring a supermarket cash register for fraudulent transactions involving a clerk and/or customer. An improved such indoor surveillance system and apparatus is shown in Paff et al. U.S. Pat. No. 4,833,534 which issued on May 23, 1989. Both of the '380 and '534 patents are commonly-assigned herewith and incorporating reference is made thereto.
The surveillance dome of the '380 patent is not specifically adapted for operation in environments undergoing extremes in temperature. On the other hand, the prior art has seen outdoor dome structure for surveillance use in which some effort is made to accomodate temperature variations. Thus, Pagano U.S Pat. No. 4,320,949 depicts an outdoor surveillance dome, including high and low temperature sensing capability and hence calling into operation respective cooling and heating apparatus. Thermostats operate an air circulation fan on high temperature sensing, moving ambient air into the dome, or operates an electrical heater on low temperature sensing However it appears that the '949 arrangement provides for continuous flow communication with ambient environment, whether the apparatus is in heating mode or in cooling mode. Further the heaters of the '949 arrangement are fixedly disposed therein and the fan is thermostatically dependent in operation. From applicants' viewpoint, the prior art outdoor surveillance dome apparatus heretofore known does not meet the current demands of performance in the environments in which use is required.